Fallen Ally and Remorse
by Dragongirl3214
Summary: Some characters are stuck in a loop of pain, torture, and suffering, Sans comes to realization of who's the most responsible. But will he be able to kill her and the demon who's infecting her? I do not own Undertale or any of the characters.
1. Chapter 1

_**Starting a new Undertale fanfic, thought it would be interesting since some of them are going really well. Well let's get the ball rolling.**_

* * *

Two beings were standing in a hall together, a monster and a human, they were preparing for a fight. The human held a knife to the monsters neck bones and the monster's eye lit up and pushed the human away from him with his magic. The human was surprised, but she continues the fight. The monster grew tired and decided to take his turn to sleep, but the human sliced its knife at him once and missed.

"You really thought you could hit," the monster started, but was cut off by the blade running across his white shirt and slicing some of his ribs.

The monster fell to his knees putting some pressure on his wound, he looked at the human his eyes having their white pupils glowing in them. The human walked up to him and he pushed himself against a pillar in the hall.

"You really are pathetic, each time I kill you," the human hissed to him.

"Not as pathetic as you," the monster said. "Chara, don't you ever get bored?"

"I keep on getting to see you like this Sansy," Chara hissed. "Besides, I haven't gotten to watch you die yet, you always walk away before I can get a good look at you dying."

"What do you want anyway," Sans asked. "Your eyes are wanting something else than to see me die."

"Well I was going to ask you a question," Chara said. "I want you to help me kill everyone, try something new."

"Go off yourself," Sans said.

"Try something new with me," Chara said. "You've been distancing yourself with everyone since the last couple of resets. You acted like you were going insane, but you weren't the other couldn't understand. So why don't you join me, we can destroy this world together."

"Like I say before," Sans said choking on his own blood. "Go off yourself."

Sans spat some blood in Chara's face.

"I remember when it was Frisk and they got us out from this hell," Sans said. "But then you appeared hidden within them, you are an insane bitch."

Chara sliced a scar across his cheekbone, Sans was starting to turn to dust.

"Well I'll see you in the next run than," Chara said.

* * *

Sans woke up in his bed back at home, he remember everything that had happened. He wasn't sure what was going on, but he knew for certain he need to go to the gate and see what is going on in this one. He needed to prepare himself for the worst, he hoped that it was the mute on that was so kind to everyone in the first timeline. He pulled on his trademark hoodie and ran out into the forest in a pair of pink slippers, he waited by the door and prepared himself for what was coming.

He then saw something the door opened and the human came from it, he got some gaster blasters ready and the human coward away from him. He saw this and got rid of them and approached the human. He bent down slightly to look into its eyes, no red within them, they were gray and staring at him in horror.

"Welcome back kiddo," Sans said happily.

The human stared at him blankly, and he pulled her into a hug. The human was confused on what was going on, but accepted the hug from Sans. Sans picked the child up and went back to his home only to be greeted by a tall lanky skeleton.

"Sans, where have you been," the skeleton asked.

"Papyrus, this is going to be our new house mate for a little while," Sans said. "She's harmless and I bet she'll even what to create some puzzles with you."

Papyrus looked at the tiny human that was balled up within Sans' arms. She stared up at Papyrus and smiled lightly to him.

"Well I guess I can't disagree with you," Papyrus said. "Well human are you going to be my new friend?"

'Yes,' the human said in sign language.

"What was that," Papyrus asked.

"Its how she speaks," Sans said. "She would love to be your new friend."

The tiny human smiled at Papyrus and he jumped with joy.

"Well I'll see you two later," Papyrus said. "I got to get to Undyne's, I have a training session."

"See you later bro," Sans said.

Papyrus left and Sans set the tiny human on their couch, he looked down at the human.

"Alright Frisk, you have to tell me what's going on," Sans said.

'Can you fill me in please,' Frisk signed.

Sans sighed and sat down beside the kid, he didn't want something bad to come to their memory.

"You killed everyone in the last timeline including me," Sans said.

Sans rubbed where Chara sliced him across his face, he was nervous about telling this to Frisk.

'Sans, that wasn't me,' Frisk signed.

"I know," Sans said. "I knew it when I saw a creepy smile on her face."

'Sans, I'm so sorry,' Frisk signed.

"It wasn't your fault kiddo," Sans said. "Besides, we can fix this all."

'What if we can't,' Frisk asked.

"We will," Sans said. "Okay kiddo, we have a long journey ahead of us. I suggest you get some sleep."

Sans yawned and Frisk nuzzled into the side of his rib cage, Sans smiled lightly and closed his eye sockets. He was asleep in a matter of minutes.

* * *

 _Sans woke up in a dream, he saw that it was the same hall he was in before with Chara. He looked around carefully and saw her standing at the end of the hall, she immediately tried to kill him. He grabbed her and put two bones into her, then he realized something it was Frisk he was killing. He released the girl and took a step back and stared down at his hands. Then the feeling of the knife going through his bones again._

* * *

He woke up in shock and held his chest, Frisk woke up along with Sans. Sans was breathing heavily and was holding where Chara got him, he was shaking as well.

'Sans, are you okay,' Frisk signed.

"I'm alright," Sans said. "I'll be alright."

'Sans, what did you see,' Frisk asked.

"Don't worry about it kid," Sans said. "Just give me a minute, I'll be fine after that."

'What's going on,' Frisk asked. 'What did I do?'

"You didn't do anything," Sans said. "Kid, don't ask again."

Sans got up from the couch and cracked some places that needed to be cracked. Someone climbed onto his back, he looked and Frisk was on his back.

"Heh, what are you doing kid," Sans asked.

Frisk moaned and Sans used his power and hold Frisk in his arms. Frisk stared up at the skeleton with endearing eyes, his white pupils staring at her.

"What's with you," Sans asked.

'Sans, I have to get going,' Frisk signed.

"I know," Sans said. "I'll be there to meet up with you somehow."

Frisk nuzzled into Sans chest and some blue blush crossed his face. She felt comfortable around the skeleton and he was indifferent towards her, the last couple of timelines had her killing everyone. He walked out the front door and placed her at the edge of Snowdin and Waterfall.

"Alright kid, continue that way and I'll meet up with you sometime," Sans said.

'You're not coming,' Frisk asked.

"No, I'm not," Sans said. "I got some work to do."

With that was gone and was standing in Grillby's, Grillby handed Sans a bottle of ketchup and Sans downed the bottle. He got some actual food and then something went of his spine, like something wasn't right. He teleported to where Frisk was and he saw her running from glowing blue spears.

"Undyne," Sans whispered.

He darted towards the fish monster and knocked her in the face with a bone, that got her attention away from Frisk. Sans teleported to Frisk and brought her back to his home.

"Alright kid, enough fun time," Sans said. "Maybe I should have walked with you into Waterfall."

'You think,' Frisk signed.

"Sorry kid," Sans said. "Alright, on to something more serious though. Have you killed anyone as of lately?"

Sans eyes went black and he stared at the kid, she twitched in her boots.

"Kid," Sans said.

'No, but something took over me and I don't know what happened after that,' Frisk said.

* * *

 _ **Ending the first part of this like that. I hope I can create some more personality to the characters as I go.**_


	2. Chapter 2

_**Another part in this series, I guess I might as well continue with it. Well here we go.**_

* * *

'It wasn't entirely Chara,' Frisk signed shyly.

"You better explain quickly kid," Sans growled his left eye a blazed.

'When I first came here, she wanted to help everyone, but in the next timeline, she told me to start killing everyone,' Frisk signed nervously. 'When we got to Toriel, the boss monster in the ruins we... we... killed her.'

Their hands were shaking and Sans could tell this wasn't the kid he met in the very first timeline.

'I understand if you're upset with me,' Frisk signed.

"You killed them," Sans growled. "You killed them in the next timeline. Why did you do it kid?"

'I can't tell you how much I regretted killing them, but by the time I was able to regain control you were dying,' Frisk signed.

"Then how come I don't remember it," Sans asked.

He was tense and his power had enveloped the two.

'Chara, she messed with something,' Frisk said. 'She told me that no one would remember anything, I guess she was right. I thought you would remember after that timeline, but you didn't.'

Sans sighed and went to the door.

'Where are you going,' Frisk asked.

"I'm going to Grillby's," Sans said. "I need to process everything that you just told me and hopefully I can regain some memories from that forgotten timeline."

He walked out of the house and walked over to Grillby's, he needed some ketchup in his system. He walked in and Grillby handed him a bottle of ketchup, he drank it more slowly and thought about what Frisk told him.

 _Am I going insane,_ Sans thought. _No, I can't be going insane, I've seen this world go through hell and back. I've seen that kid do some bad things to everyone I loved and I hope that she doesn't do anything stupid._

A feeling of dread ran up his spine intensely and he broke the ketchup bottle within his bony hand. Then nothing, he rubbed his back and looked at his hand, there was blood seeping through where the glass cut him. Grillby was right there cleaning up the mess and Sans was pull some stuck glass from his bones. Grillby wrapped it up in some damp cloths.

"Are you okay," Grillby asked.

"Yeah," Sans said

"What was that," Grillby asked. "You have never done that before."

"I don't know," Sans said. "I got to go check on something."

Sans left and went back to his house, where when he opened the door dust came out and got into his eye sockets. He rubbed his eyes and got the dust away from him enough to see inside. He saw something that made his bones rattle intensely, a red scarf in a pile of dust. He looked out the door again and saw dust footprints of Frisk's running into Waterfall. He teleported and caught up to her, he grabbed her by the shirt and pinned her up to the wall. He was pissed at her, this was not okay, he protected her and this is how she pays him back. He had to hold himself back from destroying her, turning her into dust like what she did to his brother.

"What the fuck," Sans growled. "You little shit, I trusted you."

Frisk didn't sign, she was too scared to even stare him in the eyes which his left eye was blazing blue.

"You're going to have a bad time," Sans growled. "Reset the timeline, and don't ever show your face to me again. Am I clear?"

Frisk nodded and she tapped her reset button.

* * *

Sans woke up in his bed still pissed from the last timeline, but got over it once he heard his brother walking around downstairs. He got up and pulled on his trademark hoodie and slipped on his slippers, he went down to greet his brother.

"Morning Sans," Papyrus said.

"Morning bro," Sans said. "I'm going to head out early today and see about something."

"Alright," Papyrus said.

Sans teleported to the doors and stood there, he waited to see if the kid was really going to stay in there or if he was going to turn his back on them. He didn't trust them anymore, even if it was Chara or Frisk. The door opened and he walked back to Snowdin, he should have known that they were going to come out of there. He then felt something tug on the sleeve of his sweatshirt. He turned his head slightly and stared down at the liitle girl.

'Sans, what happened in the last timeline,' She signed.

Sans responded with a growl of anger towards her and pull his sleeve out of her grip. He heard her make a sound of pain towards him, that made him turn around to her.

"You're the one who made the bad choice," Sans growled. "Now, you're going to have a bad time here. I'm not helping you, so forget about it."

Frisk tried to form words, but she couldn't, her first friend outside the ruins hated her for what she did in the last timeline.

"Can't even speak correctly to even tell me I'm sorry," Sans growled. "I thought you would know better than to kill Pap, but I guess I was wrong like I was about a lot of things."

Frisk recoiled at his comment, she walked towards him and he made bones appear in her way.

"Stay away from me and my brother," Sans growled. "You'll get your judgement from me soon enough."

Sans teleported away from her and went back home, he managed to convince Papyrus to stay home for the day. He watched and saw the tiny girl come into Snowdin, he glared at her through the window and turned his back to her. She was cold, but he didn't care one bit, she brought herself into this mess. He teleported to his station in Hotland, he grabbed a bottle of ketchup he had stored under the counter and he served some hot dogs and some hot cats. Sans sat back in his chair and waited for more customers to buy some hot dogs or hot cats.

He heard a small yelp from somewhere, then he saw the little girl stumble into the area. He looked away from her and she crawled up to his stand, but he didn't make eye contact with her.

'Sans, please forgive,' Frisk signed.

"GO AWAY," Sans yelled at her. "I told you I didn't want to see you again, so get out of here before I loose my temper!"

'Sans, let me explain,' Frisk signed.

"I'm not going to allow that to happen, get out of here," Sans growled. "I'm done protecting you and I no longer care for you kid, I hope you're happy with this timeline. Now go before I change my mind of sparing you."

"Sans," Frisk mumbled.

Sans was stunned to hear his voice come from her muted lips, but it just made him even more mad. He left eye blazing blue, he wasn't going to allow her to use him, play with him. She grabbed his jacket and pulled him into a hug, he was stunned and got mad as each passing second. Her voice turned into a whimper.

"Sans," Frisk cried.

He tried to move back or do something, but nothing, she was holding him where he was. He calmmed down and Frisk nuzzled into his cheek bone, he took a deep breath in and patted her back.

* * *

 ** _Ending it right there for now, I hope you guys like it so far. Leave a review if you like. See you guys in the next part._**


	3. Chapter 3

_**Welcome back guys let's get started.**_

* * *

"Sans," Frisk cried again.

Sans managed to pull the crying girl away from him and stare her in the eyes.

"You have three seconds to explain," Sans growled.

'It wasn't me,' Frisk signed. 'Chara took over and after I saw what she did, I ran. You thought differently, but I knew at the moment you were pissed. I knew I couldn't explain to you, but after I reset I thought you would be able to hear me out. I guess I was wrong, I'm sorry Sans."

Sans sighed and pulled her into another hug, she buried her face under his hoodie and he teleported them to his house. Papyrus stared at the two curiously, Sans set the girl of their couch and covered her with his hoodie. Frisk was asleep in a matter of minutes, Sans pulled up a chair beside her and leaned back in the chair.

"Sans, what is that," Papyrus asked.

"A human," Sans said.

"You caught a human," Papyrus asked.

"Sort of," Sans said. "She sort of found me."

"Sans, can we keep her," Papyrus asked.

"We'll see," Sans said.

"What do you mean by that," Papyrus asked.

"She's unstable right now," Sans said. "I'm going to help her keep in check."

Sans yawned out loud and leaned further into the chair he was sitting on, he close his eyes and he felt the shake from Papyrus trying to keep him awake.

"Am I not allowed to rest my bone tired bones," Sans asked.

"Are you seriously going to make puns," Papyrus screamed.

Sans jumped from the chair to cover his brother's mouth, but it was already to late Frisk was awake. Frisk stared at the two skeletal brothers from under Sans' jacket, Sans went over to her and picked her up from within his jacket.

"How are you feeling," Sans asked.

'I'm alright, what's with all the screaming,' Frisk asked.

"Sorry, Pap doesn't know how to speak softly," Sans said gently. "Alright, let's get you back on your journey, I'm still not going to help you and you'll receive your judgement from me soon. I'll see you then."

Sans teleported to where the two were before at his station in Hotland, he placed her by his stand.

"Alright get going," Sans said. "I'll see you soon."

Sans teleported away, but close enough to watch her moves carefully. He saw her interact with monsters, but she didn't hurt them at all until halfway to the core something happened and she killed multiple monsters in a row. That was the last straw, he was going to kill her when she got to Judgement Hall and there was no one that would stop his decision in this. He went to Judgement Hall and waited for the tiny human, this was going to be the end and he wasn't going to allow her to go any further with this lies and claims.

He heard her faint footsteps coming from the other end of the hall, but when he turned around he saw Chara there instead of Frisk. He saw the wrong person killing all those monster or maybe she was deguising herself to look like Frisk. He let out a growl towards her, he was done with this either way. Chara ran towards him and he grabbed her with his magic and flung her across the hall, he summoned some bones, but she managed to dodge them. He managed to hit her a couple of times before she was on the ground in pain. Sans let a demonic smile cross his face, he was going to end the one who put pain into all his friends.

"Sans," a whimper cry called from the other side distracting him from the task at hand.

He turned and saw Frisk clutching a small bottle of ketchup for him, she had tears in her eyes as she stared at what was going on. He walked towards her and reached out for her.

"Frisk its not what it seems," Sans started but was cut off by the blade of a knife going through his rib cage.

Sans collapsed to the ground as Frisk ran over to him, he looked up at her, blood slowly coming out of his mouth. He held his wound and fell forward into Frisk's lap, he was dying and Chara was laughing at his pain.

"Would you look at that," Chara hissed. "The comedian is dying, how hallirious, I thought I wouldn't be able to see this again."

Frisk moved Sans so she could see where he was hurt, Sans growled in pain as she did so and stared up into grey eyes.

"Sorry kid," Sans said.

Frisk pulled her soul out from her body and held it towards Sans, he stared at her.

'Take it,' Frisk signed. 'Kill her and reset the timeline.'

Chara lashed forward, but before she could grab Frisk's soul, Sans' bloodily hand grabbed it first. Something powerful went through him and he was completely healed and his magic felt more powerful.

"I took you for granted kid," Sans mumbled to himself.

Chara growled at him and he tilted his head, this was going to be fun for him.

"Let's go at it one more time," Sans said.

Chara ran at Sans, but he teleported above her and summoned a gaster blaster. Chara dodged and flung her knife at Sans, but he caught it before it could even hit him and stuck it high in a wall. He used his magic to concentrate on Chara and he flung her about the room, he summoned bones and skewered her to the ground.

"GET DUNKED ON," Sans cheered.

Something pounded from within his rib cage and he lifted his shirt to see the red soul next to his monster soul.

"Alright kid, I'm on it," Sans said. "Don't worry about it, I'll protect you from now on."

He managed to reset the timeline.

* * *

He woke up in his bed and yawned, he shook some pain from his bones and stared ahead. He found that he had his hoodie on and his slippers, he teleported to the door in the woods. Someone was already waiting for him at the door though, Chara held Frisk within one of her arms.

Sans growled a little and summoned a gaster blaster. Chara made her big devilish smile towards him and it made him angrier than what he already was.

"Sans," Frisk choked on his name.

"You're such an idoit Sans," Chara hissed. "You never learn do you."

Sans used his power to hold Chara up and away from Frisk, he grabbed the kid and held her behind him. He wasn't going to allow this demon to hurt Frisk or anyone else. Then suddenly a sharp pain in Sans' left eye.

* * *

 _ **I'm going to end it right there on a cliffhanger for now. I hope you guys like it, leave a review if you like. See ya.**_


	4. Chapter 4

_**Welcome back let's get started shall we.**_

* * *

The cold blade of the knife went into Sans' eye that helps him control his power, now there was blood pouring out of the wound.

"Sans," Frisk's cry said to him.

He shook his head and put a hand over his eye so Frisk didn't have to see it. She held onto his right sleeve and stared up at him, he growled towards Chara.

"What's the matter Sansy," Chara hissed. "Are you going to punish me?"

"Go the fuck away," Sans growled. "As much as I would like to dye this snow red, I don't want to do it in front of Frisk here."

"That mute little brat, she killed you more than once," Chara said. "Yet you still protect her."

"I'm not protecting her from any monsters here," Sans said simply. "I'm protecting her from the true monster of the Underground."

"You cheeky little bastard," Chara said.

"I am because you're the reason why my father is dead," Sans growled. "So let's get our facts straight here, you purposefully pushed Gaster, my and Papyrus father, into the Core because he wasn't listening to you. I know all about it, I saw it happen I was just a baby bones with my brother, but you had the guts to do it. We were suppose to be friends, but you ruined it."

"Ha," Chara laughed. "I thought you were stupid at the time, but it looks like the trashbag has it all figured out now."

Sans growled out towards her and Frisk buried her face into his jacket.

"Kid, go get Pap," Sans said to Frisk.

Frisk held tighter to Sans.

"Kid, don't do this to me," Sans said. "Go now, I'll continue to deal with this trash."

Frisk reluctantly ran off going to get the other skeleton.

"Now where were we," Sans asked. "Oh I remember."

Sans summoned bones and flung them at Chara, she dodged them and tried to slice Sans with her knife. He managed to dodge her, but she got the edge of his jacket. He saw her running up behind him and he jumped over her and smacked her with a bone in the back of the head, he landed on the ground a little hard and he heard something start to crack. His one leg bone was starting to crack, he shot some more bones at Chara and she was impaled by them, but she still came at him.

"You're stupid Sans," Chara growled.

Sans grabbed her arm and she laughed out.

"You're weak," Chara hissed. "I remember when I first met you, you were so full of life wanting to do everything and anything. You encouraged your brother to be just like you, you were part of the royal gaurd and since that timeline you turned into trash."

"Why should I work for something that has no meaning in the long run," Sans growled his grip starting to fail him. "You knew it was going to reset anyway, I knew it all along and because of that this is what I am today."

A bone flew into Chara's chest and Sans looked over his shoulder and saw his brother and Frisk with Undyne. Sans smiled, but it was short lived. Something went through him and he looked down and saw Chara's hand with the knife coming through his rib cage.

"Welp, I guess that's it then," Sans said falling to the ground.

Chara died right there and Frisk had Sans' head in her lap, tears were running down her face.

"What's with the upset face kiddo," Sans asked. "I'll be alright."

"No you won't," Frisk choked out.

"You can speak now," Sans said. "Great, happy to hear that we can actually speak now. I'll see you in the rest run kid."

Frisk held their dying friend closer to her, Sans breathing became ragged and he carefully took off his jacket and wrapped it around Frisk's body.

"I don't want you to be chilled to the bone," Sans said choking on his own blood. "Heh, one last joke before I kick the bucket."

"No die," Frisk cried. "Ketchup?"

"Its not ketchup bud," Sans said.

Slowly Sans was turning to dust, he closed his eyes.

"One final nap," Sans said.

* * *

Sans woke up in his bed, he coughed slightly and rubbed where Chara stabbed him in the chest. He didn't have his sweatshirt on and he couldn't find it within his room, then he heard a knock at his door. He got up slowly and went over to it, he opened the door only to reveal a Frisk with his jacket.

"Heh, its a bit big on you," Sans joked.

"Sans," Frisk said hugged him.

Sans smiled lightly and rubbed her back, he saw his brother behind her in utter confusion.

"Oh I see you've already met the human somehow," Papyrus said. "I didn't even see you come out of your room this morning, so how she got your jacket was beyond me."

"She's an old friend," Sans said. "Plus I think she'll even be your friend if you ask her."

"So human will you be my friend," Papyrus asked the tiny human.

'Yes,' Frisk signed.

"She said yes," Sans said. "Don't worry Pap."

Papyrus jumped with joy and went off on his day, Sans pulled Frisk into his room and tried to get his sweatshirt off her. Frisk crossed her arms and pouted to him, Sans wasn't amused one bit and he lifted her with the use of his power.

"Can I have my sweatshirt back before you have a bad time," Sans said.

Frisk shook her head and Sans sighed and summoned some gaster blasters around her. He made them inch closer to her, then he made them swarm her and nuzzle her.

"Can I have it back now," Sans asked.

His sweatshirt flew out from the swarm of blasters, he made them disappear and put his jacket on. Frisk sat on the floor dazed beyond belief, she wasn't hurt or anything. Sans stood over her and allowed his one eye glow with a gentle blue glow, she pulled her sweater above her nose and stared up at him.

"Heh, come here," Sans said holding out a hand gently to her.

Frisk let him help her to her feet, Sans sighed and walked out of his room. Frisk's small cry echoed in his ears, she hugged him from behind and buried her face in the short skeleton's spine. Sans used his power to put Frisk on his shoulders, Frisk wrapped her arms around Sans' forehead.

"Alright let's get going," Sans said walking downstairs.

The skeleton was going to be cautious around Frisk, but he knew when they would act up and Chara would try to come out. I guess Frisk had her in check now, Sans let the little girl down and she was being gentle to everything. Then he saw her walk into a room, he followed her only to see someone he thought was dead.

"D... da... dad," Sans stuttered. "Gaster."

The being standing next to Frisk stared at Sans, his large smile similar to Sans' but was strangely different.

"She's not dead Sans," Gaster said. "Chara, is out there, away from Frisk's body and she's coming after you."

"Like I didn't know that already," Sans said.

* * *

 ** _Ending it right there for now, I'm going to hopefully explain everything in the next part of this._**


	5. Chapter 5

"Sans, its been do long," Gaster said.

"I know," Sans said. "I thought I wouldn't see you again after Chara you know."

"Yeah, but there's something that I need to tell you," Gaster said. "When Chara was still alive, she had a secret of wanting to kill every monster in the Underground starting with Asgore. I knew it at the time and I was going to tell him, but the Core was malfunctioning for some odd reason. When I went to see what was going on, Chara and Asriel, they both were messing with the Core's functions. I tried to stop them, but when I finally got it under control, Chara pushed me into the Core."

"I saw that part," Sans said. "I know she wants to destroy everything, but my only question is why? Why kill everything?"

"She had no love," Gaster said.

"I should have guessed that," Sans said. "Is that all?"

"Yes," Gaster said. "I'll be going and tell your brother that I said I love you both."

"I'll make sure he gets the message," Sans said.

"Good luck, my son," Gaster said disappearing.

Frisk ran over to Sans and he picked her up in his arms, she wrapped her arms around his neck.

"So kid, let's continue our journey then," Sans said walking around.

The two walked forward into Waterfall until they ran into a female fish monster.

"Sans, give me the human," she demanded.

"Undyne, I'm not going to do that and you know it," Sans said.

"Sans, I will kill you if you don't give her to me," Undyne yelled.

Frisk was trying to get Sans to give her up to Undyne, but Sans wasn't going to allow himself to do so. Sans set Frisk behind him and stared at Undyne with lifeless eyes.

"Sans, don't make this hard," Undyne said. "You're my friend and I don't want to hurt you."

"Same here," Sans said. "But you won't let me pass with the human."

Undyne launched a spear at Sans, but he wasn't quick enough to move Frisk out of the way. Her health went down and he had to hold her within his arms, he became angry at Undyne.

"You didn't know her," he said in a unsettling calm voice. "And you attacked her without even getting to know her."

Sans stared at Undyne his left eye blazing blue, he held the small human to him.

"You're going to have a bad time now," Sans growled.

Sans set the tiny human a safe distance away from the two monsters.

"Sans's got to dunk someone," Sans whispered into Frisk's ear.

"Dad, no fight," Frisk muttered.

Sans was stunned to hear the tiny girl call him dad, but I guess she wasn't wrong. He kept her safe and protected her like a dad, but he had other matters to attend to than to tell the girl he wasn't. He stood up and faced the fish monster head on, he had never really had the chance to fight Undyne and he wasn't going to let her go easy on him. He was going to protect Frisk and keep his promise to Toriel.

"Alright Sans," Undyne said.

"Ready," Sans asked.

Sans raised his one arm and locked onto Undyne's soul, he flung her down and he summoned a couple of gaster blasters. Undyne was strong enough to resist his magic slightly and got up and launched a couple of spears, Sans teleported behind her and slightly above. He hit her in the back of the head with a bone and knocked her over with a gaster blaster.

"Sans what the hell," Undyne asked.

"You see Undyne, when I'm prepared for a fight, I'm ready to give my all for someone that's worth protecting," Sans said. "There's someone else that you should be worrying about."

Sans stood over Undyne and he looked down at her, she was scared out of her wits and he knew it. Sans smile gave off a devilish intention and he raised his hand one last time until some grabbed his arm. He looked over and saw Frisk holding onto it desperately, he calmed down a little and looked back at Undyne.

"Undyne, she doesn't mean any harm to any of us," Sans said. "She just wants to set us free and I'm going to make sure she doesn't die along the way. So will you please just spare us just this once, I won't tell anyone."

"Why would I do that," Undyne growled.

"Look at this kid," Sans said. "She's forcing me to spare you, I would have killed you by now if I could. Please just do this and we'll prove it to you later."

"Fine, but you better make sense later on," Undyne said sparing the two.

"Thank you, we'll meet up later," Sans said. "Come on kid let's get you somewhere you can rest."

Sans held Frisk and the two walked off to Hotland where Alphys was outside taking temperatures and readings.

"Oh Sans just the monster I wanted to see," Alphys said. "What do you have there?"

"This is Frisk," Sans said. "She's my little buddy for the time being."

"Well I saw someone like her pass by not to long ago," Alphys said. "She was killing monsters, I sent Mettaton after her."

"Watch after this one, I'm going to go off and handle the other," Sans said setting the little girl on the ground next the Alphys. "She needs to rest, a fight with Undyne, but she spared her."

"Well that's good to hear, but what about the other," Alphys asked.

"Let me handle her," Sans said teleporting ahead.

He saw the human standing in front of him, she had dust covering her front half.

"Hello Sansy," Chara hissed.

"Don't call me that," Sans said. "You know why I'm here."

"Don't tell me," Chara said putting the knife to her lip. "Monsters."

"Sometimes, you're too crazy for me to handle," Sans said.

"Maybe that's a good thing," Chara said. "Why don't you join me in killing everyone here? You'll have protection from me destroying everyone here."

"I won't do that," Sans said. "You know that, I have standards like my brother, but I will never ever harm an innocent. So why don't you go to hell and stay there for all I care."

"Sorry, I've been there and your dad is really a nice guy," Chara said.

Sans's left eye lit up and he threw some bones at her.

"Don't you dare talk about him that way," Sans growled.

"He created you to be the one at the end to put the humans where they belong," Chara said. "He didn't want sons, he wanted one where he could protect those at the beginning and another stronger one at the end. You are the Judgement while Papyrus is the one to decide weather they are allowed to pass."

Sans growled inwardly and he didn't like the way she was talking about his father, he knew that his father loved him and Papyrus both. Chara was trying to get under his bones, he raised his hand and threw bones the impaled her body to the ground.

"Now I am going to help Frisk out of here and get everyone out of here too," Sans said to the dying girl.

He used his magic to throw the girl into the lava below, he sighed and teleported back to Alphys and Frisk.


	6. Chapter 6

Sans found the little human asleep on a couch Alphys had and he bent down beside her. She was tired and he could tell, he looked over at Alphys. Alphys seemed a little concerned.

"Is the other one gone," Alphys asked.

"Yeah I made sure about that," Sans said. "She won't be coming back anytime soon, so Frisk here we'll be safe for now."

"Sans, what's that behind you," Alphys asked.

Sans turned his head and he saw a golden flower with an evil smile on its face.

"Howdy Smiley Trashbag," the flower said.

"F-f-f-flowey," Alphys said.

Vine shot into Sans's chest and wrapped around his rib cage and soul, Sans teleported into a secluded area in Waterfall. He screamed until he felt like his throat was sore. Flowey was able to take control over Sans with ease, Sans was still able to see out of his own eyes.

"Well you made it too easy to take over you trash," Flowey said. "Let's go take care care of the kid."

 _Stay away from her,_ Sans thought.

"What are you some kind of parent to the child," Flowey hissed. "You're nothing to her and you seen that little shit kill you more times that you have fingers and toes."

 _Makes me want to protect them from things like you,_ Sans thought. _I already got rid of Chara, so why don't you give up and let me go. I'll spare you if you spare me right now, if not you're going to have a bad time._

"No, like I want your pathetic sparing," Flowey said. "Let's get going I got people to kill and places to destroy."

Flowey forced Sans to move his body, and he did it painfully. They wound up outside Alphys lab in a matter of hours, Sans tried to resist, but he wasn't able to. He was forced to kill several monsters along the way, he wanted to kill himself after each battle. Alphys protected the kid and the three monster began to fight.

"Alphys, don't hold back," Sans groaned. "Kill me and don't let the kid see, tell them I'm doing something else."

"Sans," Alphys said.

Flowey made him use his magic to attack her and she dodged it and came back at him, he was faster than her by a long shot and used magic on her again.

"Alphys please," Sans said.

Flowey tried to get him attack again, but Sans held out his arms in submission.

"Do it," Sans screamed.

Alphys was about to use her magic when something else tackled Sans to the ground. Frisk had Sans on the ground and he stared up at her, she had tears building up in her eyes. That caused him to have to build up of tears in his eyes, he didn't want to see the kid like that.

"Well looky here Sans," Flowey hissed. "Someone is actually going to see you die."

"Kid, run," Sans moaned. "Or kill me right here. I don't care, just do it quickly."

Frisk held a small scalpel to Sans's chest, Frisk dug the scalpel across his chest. Sans bled, but it got Flowey off him and he clutched his wound on his chest. Frisk looked down at her fallen friend.

"Sans," Frisk wined.

"I'm going to die no matter what," Sans said. "Stay here and then continue on without me."

Frisk hummed a little tune that she had heard on the surface with Sans, while he was walking her to her school. It was something that someone had blaring on the car and Frisk wanted to know the name, it took him all day to find out the name and download it onto his computer.

"Musing through memories," Sans sang lightly. "Loosing my grip in the grey, numbing the senses, I feel you slipping away."

Frisk was now crying as she hummed it.

"Fighting to hold on," Sans sang quietly. "Clinging to just one more day love turns to ashes, with all that I wish I could say."

"I'd die to be where you are," Frisk sang. "I tried to be where you are."

"Every night, I dream you're still here," the two sang. "The ghost by my side, so perfectly clear. When I awake, you'll disappear, back to the shadows with all I hold dear."

"With all I hold dear," Sans sang lightly.

"I dream you're still here," Frisk sang.

"I dream you're still here," Sans sang. "Hidden companion, phantom be still in my heart make me a promise that time won't erase, that we were not lost from the start."

"I'd died to be where you are," Frisk sang crying. "I tried to be where you are."

"I dream you're still here, ever slightly out of reach," they sang together. "I dream you're still here, but it breaks so easily. I try to protect you, I can't let you fade."

"I feel you slipping," Frisk sang. "I feel you slipping away."

Sans was turning to dust slowly, leaving his hoodie where he was.

"I dream you're sill here," Frisk sang.

"Every night I dream you're still," Sans sang closing his eyes. "Every night I dream you're still here."

"I dream you're still here," Frisk sang.

"Every night I dream you're still," Sans sang his eyes closed. "Every night I dream you're still here."

Frisk cried.

"But it breaks so easily," Frisk cried out.

"I'll always be in your soul, kiddo," Sans whispered before completely turning to dust without his sweatshirt.

Sans's soul floated to her face and rubbed it before disappearing, Frisk clung to his sweatshirt and cried out.

"Wait, he's still here," Alphys said running to the small girl. "Let me see his sweatshirt and we'll get him back."

Alphys took Frisk to her secret lab, she placed his sweatshirt within a machine and turned it on. Frisk had tears streaming down her face, Alphys tried to comfort the small human.

* * *

 _ **I used the song as Sans died its called "Still here" by Digital Daggers.**_


End file.
